Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Paleontologists discover new fossil organism

12.05.2014

Likely related to our ancestors, 'Plexus ricei' was much like a tapeworm or modern flatworm, say UC Riverside researchers

Scientists at the University of California, Riverside have discovered a fossil of a newly discovered organism from the "Ediacara Biota" — a group of organisms that occurred in the Ediacaran period of geologic time.


This image shows a reconstruction of Plexus ricei.

Credit: Droser Lab, UC Riverside.

Named Plexus ricei and resembling a curving tube, the organism resided on the Ediacaran seafloor. Plexus ricei individuals ranged in size from 5 to 80 centimeters long and 5 to 20 millimeters wide. Along with the rest of the Ediacara Biota, it evolved around 575 million years ago and disappeared from the fossil record around 540 million years ago, just around the time the Cambrian Explosion of evolutionary history was getting under way.

"Plexus was unlike any other fossil that we know from the Precambrian," said Mary L. Droser, a professor of paleontology, whose lab led the research. "It was bilaterally symmetrical at a time when bilaterians—all animals other than corals and sponges—were just appearing on this planet. It appears to have been very long and flat, much like a tapeworm or modern flatworm."

Study results appeared online last month in the Journal of Paleontology.

"Ediacaran fossils are extremely perplexing: they don't look like any animal that is alive today, and their interrelationships are very poorly understood," said Lucas V. Joel, a former graduate student at UC Riverside and the first author of the research paper. Joel worked in Droser's lab until June 2013.

He explained that during the Ediacaran there was no life on land. All life that we know about for the period was still in the oceans.

"Further, there was a complete lack of any bioturbation in the oceans at that time, meaning there were few marine organisms churning up marine sediments while looking for food," he said. "Then, starting in the Cambrian period, organisms began churning up and mixing the sediment."

According to the researchers, the lack of bioturbators during the Ediacaran allowed thick films of (probably) photosynthetic algal mats to accumulate on ocean floors—a very rare environment in the oceans today. Such an environment paved the way for many mat-related lifestyles to evolve, which become virtually absent in the post-Ediacaran world.

"The lack of bioturbation also created a very unique fossil preservational regime," Joel said. "When an organism died and was buried, it formed a mold of its body in the overlying sediment. As the organism decayed, sediment from beneath moved in to form a cast of the mold the organism had made in the sediment above. What this means is that the fossils we see in the field are not the exact fossils of the original organism, but instead molds and casts of its body."

Paleontologists have reported that much of the Ediacara Biota was comprised of tubular organisms. The question that Droser and Joel addressed was: Is Plexus ricei a tubular organism or is it an organism that wormed its way through the sand, leaving a trail behind it?

"In the Ediacaran we really need to know the difference between the fossils of actual tubular organisms and trace fossils because if the fossil we are looking at is a trace fossil, then that has huge implications for the earliest origins of bilaterian animals—organisms with bilateral symmetry up and down their midlines and that can move independently of environment forces," Joel said. "Being able to tell the difference between a tubular organism and a trace fossil has implications for the earliest origins of bilaterian organism, which are the only kinds of creatures that could have constructed a tubular trace fossil. Plexus is not a trace fossil. What our research shows is that the structure we see looks very much like a trace fossil, but is in fact a new Ediacaran tubular organism, Plexus ricei."

Plexus ricei was so named for plexus, meaning braided in Latin, a reference to the organism's morphology, and ricei for Rice, the last name of the South Australian Museum's Dennis Rice, one of the field assistants who helped excavate numerous specimens of the fossil.

"At this time, we don't know for sure that Plexus ricei was a bilateral but it is likely that it was related to our ancestors," Droser said.

###

She and Joel were joined in the research by James G. Gehling at the South Australian Museum. Joel is now a Ph.D. graduate student at the University of Michigan, Ann Arbor.

The research was funded by grants from the National Science Foundation and NASA to Droser; a National Science Foundation Graduate Research Fellowship to Joel; and a grant from the Australian Research Council to Gehling.

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | Eurek Alert!

Further reports about: Foundation Plexus Riverside UCR bioturbation fiber implications oceans

More articles from Earth Sciences:

nachricht Past and present sea levels in the Chesapeake Bay Region, USA
29.07.2015 | Geological Society of America

nachricht “Carbon sink” detected underneath world’s deserts
29.07.2015 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>